Modeling of Moisture Transfer in Food Systems Packed in Polysaccharide-Based Films

The stability of food products depends upon the type of packaging used for their containment. The overuse of synthetic polymers has originated serious environmental issues in past years. To curb this, alternate packaging materials made from the biological materials are being adopted in food industries. One type of these packaging films is based upon the polysaccharides, which are hydrophilic in nature. Thus, the moisture migration from the foods packaged in these films is needed to be analyzed using modeling equations. Diffusion is the primary phenomenon responsible for mass transfer through these films, and its rate is influenced by food as well as surrounding conditions. Considering this, models are conceptualized on the basis of food, package type, and its properties and environmental conditions. Sorption is a common process of gaining (adsorption) and loosing moisture (desorption) until equilibrium is attained in processed foods. Models like Guggenheim, Anderson, and de Boer (GAB) and Brunauer, Emmett, and Teller (BET) are widely used to describe the behavior of foods under constant temperature and relative humidity. Transpiration and respiration processes are common with the fresh produce. Theoretical and gravimetric approaches explain the moisture migration behavior through films due to transpiration. In respiration modeling, Arrhenius equation describes the temperature dependency, and enzyme kinetics explains inhibition due to carbon dioxide on respiration rates. These models either single or in combinations are helpful in determining moisture transfer through polysaccharide-based films for one or multicomponent foods.